How Can I Get Back WeChat Images When iPhone Update To iOS 12?

Hello guys! I've updated my iPhone 7 to the latest iOS 12. Since then, I've lost all my WeChat photos for unknown reason. Thankfully, I synced my iPhone to iCloud before, is there any chance that I can get only WeChat images from my backup? Refer to the previous cases and experience, It is a common situation that a large number of iOS users would lose their vital data after an update. Well, if you have backed up your iPhone to iCloud or iTunes, it can be a difficult task to find your lost...